The Two Spring Systems: Torsion vs Extension
Garage doors use one of two spring systems. Torsion springs mount horizontally above the door on a metal shaft. They wind tight when the door closes, storing energy to lift 150+ pounds of door weight. Most residential doors in Miami-Dade and Broward built after 1990 use torsion springs—they're safer and last longer in our humid climate.
Extension springs run parallel to the horizontal tracks on both sides of the door. They stretch and contract as the door moves. Older homes and budget builder-grade doors often have extension springs. They're easier to replace but fail more frequently—humidity and salt air accelerate metal fatigue.
Knowing which system you have takes one glance. Look above the door when it's closed. See a thick spring wrapped around a horizontal bar? That's torsion. See two long springs running along the tracks? Extension springs.
Visual Signs Your Torsion Spring Broke
A broken torsion spring announces itself. The most obvious sign: a 2-3 inch gap in the spring coil above the door. The spring snaps at its weakest point, leaving a clean break you can spot from across the garage. You might also see the loose end sticking out at an angle.
Torsion springs break with a loud bang—homeowners often mistake it for a car backfire or gunshot. If you heard that sound and your door suddenly weighs 200 pounds when you try to lift it manually, the spring failed. The door will only rise 6-12 inches before dropping back down, even with the opener running. Modern openers sense the imbalance and stop to prevent motor burnout.
Check the cables too. Torsion spring failures sometimes cause the lift cables to go slack or wind incorrectly on the drums. If one cable hangs loose while the other stays taut, the spring on that side broke. Don't try to operate the door—you risk cable whip or drum detachment.
In Miami's HVHZ (High Velocity Hurricane Zone), many post-Andrew homes have two torsion springs for code compliance. If one breaks, the door might still lift—barely. It'll shake, grind, and strain the opener. That's your cue to shut down and call for professional spring repair before the second spring fails or the opener burns out.
Visual Signs Your Extension Spring Broke
Extension spring failures look different. One side of the door sags lower than the other when you try to open it—sometimes by 12+ inches. The door tilts at an angle because one spring still works while the other hangs limp along the track.
Look for a stretched-out spring with a visible break near the pulley or mounting bracket. Extension springs don't snap with a dramatic gap like torsion springs—they elongate and separate at a stress point. You might see the spring still attached at both ends but with 6-8 inches of loose coil sagging in the middle.
The safety cable running through the spring tells the story. If the spring broke, the cable might be the only thing preventing the spring from flying across the garage. Never remove a safety cable—that stretched metal holds dangerous tension even after failure.
Extension spring doors often have two springs. If only one breaks, the door can still open—but it'll pull hard to one side and jam in the tracks. Stop using it immediately. Operating a door with one working spring destroys the opener and bends the track.
Why the Side Matters (Left vs Right Spring)
Torsion springs don't have a left or right—they're sized by inside diameter, wire gauge, and length. But installers do wind them in opposite directions. The spring on the left winds clockwise; the right winds counterclockwise. This balances the torque and keeps the door level.
When one torsion spring breaks, pros replace both springs. Here's why: springs are sold in matched pairs wound for the same cycle count. If one breaks at 9,000 cycles, the other is equally worn. Replacing just one leaves you with a 10-year-old spring paired with a new one. The old spring fails within weeks, and you pay for two service calls instead of one.
Extension springs, on the other hand, are left- and right-specific because of how the pulleys and safety cables route. A right-side extension spring won't work on the left. The good news: you can replace just one extension spring if the other still has life left. But most techs recommend replacing both—springs wear at the same rate, and mismatched tension causes uneven door travel.
What Happens If You Operate the Door with a Broken Spring
Don't. Even once. A garage door opener is rated for 15-20 pounds of lift force—just enough to overcome friction and momentum. The springs do 95% of the work, counterbalancing the door's weight. When a spring breaks, you ask a 1/2-hp motor to lift 150+ pounds. The opener runs for 5-10 seconds before the thermal overload kicks in and shuts it down. Repeat that a few times and you burn out the motor or strip the drive gear.
Manual operation is just as risky. A door with a broken spring weighs its full dead weight—often 180-250 pounds depending on size and whether it's insulated. Lift it halfway and let go, and it'll slam down at full speed. Cable drums spin freely, cables whip off the pulleys, and fingers get crushed in track joints. Coastal humidity makes steel tracks slippery—add 200 pounds of falling door and you have a recipe for serious injury.
In Florida's hurricane-rated zones, a broken spring compromises your wind-load protection. HVHZ doors need balanced tension to seal properly against wind-driven rain. A tilted, sagging door leaves gaps that let water intrude during storms.
Spring Lifespan: Why They Break When They Do
Torsion springs are rated for 7,000 to 30,000 cycles, depending on the wire gauge and coating. A cycle is one full open-close. Most households hit 1,500 cycles per year—four trips in and out daily. A 10,000-cycle spring lasts 6-7 years. If you have teenagers or run a home business, expect 4-5 years.
Miami's humidity accelerates fatigue. Bare steel springs rust at the coil contact points, creating weak spots. Galvanized and oil-tempered springs fare better but still corrode over time. Salt air near the coast eats through coatings faster—Brickell, Key Biscayne, and Hollywood Beach homes see shorter spring life than inland Kendall or Hialeah properties.
Extension springs wear faster because they stretch and contract fully with every cycle. They're rated for 5,000-10,000 cycles max. The pulleys introduce friction and wear points. Safety cables fray. After 5-6 years in South Florida, extension springs are living on borrowed time.
Oversize doors (16×7 or double 16×8 models) stress springs harder. So do insulated steel doors—they weigh 50 pounds more than non-insulated. If your builder cheaped out and installed 7,000-cycle springs on a heavy door, expect failure in 3-4 years.
DIY Diagnosis Is Smart; DIY Replacement Is Not
You can safely identify a broken spring without touching anything. Look, don't touch. Take photos. Note whether it's torsion or extension, count the number of springs, and check for rust or cable issues. That's enough information to get an accurate quote over the phone.
But replacing garage door springs yourself is a different story. Torsion springs store 200+ foot-pounds of torque. Unwinding them requires specialty winding bars and a methodical 20-step process. Miss a step and the spring uncoils at 400 mph, breaking hands and faces. Extension springs under tension can snap back and impale. YouTube makes it look simple. It's not.
Florida law requires licensed contractors for spring replacement in commercial settings and multi-unit residential. Homeowners can legally DIY their own springs, but insurance won't cover injuries or property damage from amateur repairs. If the spring whips loose and dents your car or breaks a window, you're on the hook.
Professional techs arrive with pre-wound springs sized to your door, calibrated winding tools, and the experience to adjust cable tension and drum alignment in one visit. Most spring repairs take 45-60 minutes from diagnosis to testing. The cost difference between DIY and pro? About $100—not worth the injury risk.